2 * bridges.c: Implementation of the Nikoli game 'Bridges'.
6 * - The solver's algorithmic design is not really ideal. It makes
7 * use of the same data representation as gameplay uses, which
8 * often looks like a tempting reuse of code but isn't always a
9 * good idea. In this case, it's unpleasant that each edge of the
10 * graph ends up represented as multiple squares on a grid, with
11 * flags indicating when edges and non-edges cross; that's useful
12 * when the result can be directly translated into positions of
13 * graphics on the display, but in purely internal work it makes
14 * even simple manipulations during solving more painful than they
15 * should be, and complex ones have no choice but to modify the
16 * data structures temporarily, test things, and put them back. I
17 * envisage a complete solver rewrite along the following lines:
18 * + We have a collection of vertices (islands) and edges
19 * (potential bridge locations, i.e. pairs of horizontal or
20 * vertical islands with no other island in between).
21 * + Each edge has an associated list of edges that cross it, and
22 * hence with which it is mutually exclusive.
23 * + For each edge, we track the min and max number of bridges we
24 * currently think possible.
25 * + For each vertex, we track the number of _liberties_ it has,
26 * i.e. its clue number minus the min bridge count for each edge
28 * + We also maintain a dsf that identifies sets of vertices which
29 * are connected components of the puzzle so far, and for each
30 * equivalence class we track the total number of liberties for
31 * that component. (The dsf mechanism will also already track
32 * the size of each component, i.e. number of islands.)
33 * + So incrementing the min for an edge requires processing along
35 * - set the max for all edges crossing that one to zero
36 * - decrement the liberty count for the vertex at each end,
37 * and also for each vertex's equivalence class (NB they may
39 * - unify the two equivalence classes if they're not already,
40 * and if so, set the liberty count for the new class to be
41 * the sum of the previous two.
42 * + Decrementing the max is much easier, however.
43 * + With this data structure the really fiddly stuff in stage3()
44 * becomes more or less trivial, because it's now a quick job to
45 * find out whether an island would form an isolated subgraph if
46 * connected to a given subset of its neighbours:
47 * - identify the connected components containing the test
48 * vertex and its putative new neighbours (but be careful not
49 * to count a component more than once if two or more of the
50 * vertices involved are already in the same one)
51 * - find the sum of those components' liberty counts, and also
52 * the total number of islands involved
53 * - if the total liberty count of the connected components is
54 * exactly equal to twice the number of edges we'd be adding
55 * (of course each edge destroys two liberties, one at each
56 * end) then these components would become a subgraph with
57 * zero liberties if connected together.
58 * - therefore, if that subgraph also contains fewer than the
59 * total number of islands, it's disallowed.
60 * - As mentioned in stage3(), once we've identified such a
61 * disallowed pattern, we have two choices for what to do
62 * with it: if the candidate set of neighbours has size 1 we
63 * can reduce the max for the edge to that one neighbour,
64 * whereas if its complement has size 1 we can increase the
65 * min for the edge to the _omitted_ neighbour.
67 * - write a recursive solver?
79 /* Turn this on for hints about which lines are considered possibilities. */
83 /* --- structures for params, state, etc. --- */
87 #define PREFERRED_TILE_SIZE 24
88 #define TILE_SIZE (ds->tilesize)
89 #define BORDER (TILE_SIZE / 2)
91 #define COORD(x) ( (x) * TILE_SIZE + BORDER )
92 #define FROMCOORD(x) ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 )
94 #define FLASH_TIME 0.50F
99 COL_HIGHLIGHT, COL_LOWLIGHT,
100 COL_SELECTED, COL_MARK,
109 int islands, expansion; /* %age of island squares, %age chance of expansion */
110 int allowloops, difficulty;
113 /* general flags used by all structs */
114 #define G_ISLAND 0x0001
115 #define G_LINEV 0x0002 /* contains a vert. line */
116 #define G_LINEH 0x0004 /* contains a horiz. line (mutex with LINEV) */
117 #define G_LINE (G_LINEV|G_LINEH)
118 #define G_MARKV 0x0008
119 #define G_MARKH 0x0010
120 #define G_MARK (G_MARKV|G_MARKH)
121 #define G_NOLINEV 0x0020
122 #define G_NOLINEH 0x0040
123 #define G_NOLINE (G_NOLINEV|G_NOLINEH)
125 /* flags used by the drawstate */
126 #define G_ISSEL 0x0080
127 #define G_REDRAW 0x0100
128 #define G_FLASH 0x0200
129 #define G_WARN 0x0400
130 #define G_CURSOR 0x0800
132 /* flags used by the solver etc. */
133 #define G_SWEEP 0x1000
135 #define G_FLAGSH (G_LINEH|G_MARKH|G_NOLINEH)
136 #define G_FLAGSV (G_LINEV|G_MARKV|G_NOLINEV)
138 typedef unsigned int grid_type; /* change me later if we invent > 16 bits of flags. */
140 struct solver_state {
141 int *dsf, *comptspaces;
142 int *tmpdsf, *tmpcompspaces;
146 /* state->gridi is an optimisation; it stores the pointer to the island
147 * structs indexed by (x,y). It's not strictly necessary (we could use
148 * find234 instead), but Purify showed that board generation (mostly the solver)
149 * was spending 60% of its time in find234. */
151 struct surrounds { /* cloned from lightup.c */
152 struct { int x, y, dx, dy, off; } points[4];
153 int npoints, nislands;
159 struct surrounds adj;
163 int w, h, completed, solved, allowloops, maxb;
164 grid_type *grid, *scratch;
165 struct island *islands;
166 int n_islands, n_islands_alloc;
167 game_params params; /* used by the aux solver. */
168 #define N_WH_ARRAYS 5
169 char *wha, *possv, *possh, *lines, *maxv, *maxh;
170 struct island **gridi;
171 struct solver_state *solver; /* refcounted */
174 #define GRIDSZ(s) ((s)->w * (s)->h * sizeof(grid_type))
176 #define INGRID(s,x,y) ((x) >= 0 && (x) < (s)->w && (y) >= 0 && (y) < (s)->h)
178 #define DINDEX(x,y) ((y)*state->w + (x))
180 #define INDEX(s,g,x,y) ((s)->g[(y)*((s)->w) + (x)])
181 #define IDX(s,g,i) ((s)->g[(i)])
182 #define GRID(s,x,y) INDEX(s,grid,x,y)
183 #define SCRATCH(s,x,y) INDEX(s,scratch,x,y)
184 #define POSSIBLES(s,dx,x,y) ((dx) ? (INDEX(s,possh,x,y)) : (INDEX(s,possv,x,y)))
185 #define MAXIMUM(s,dx,x,y) ((dx) ? (INDEX(s,maxh,x,y)) : (INDEX(s,maxv,x,y)))
187 #define GRIDCOUNT(s,x,y,f) ((GRID(s,x,y) & (f)) ? (INDEX(s,lines,x,y)) : 0)
189 #define WITHIN2(x,min,max) (((x) < (min)) ? 0 : (((x) > (max)) ? 0 : 1))
190 #define WITHIN(x,min,max) ((min) > (max) ? \
191 WITHIN2(x,max,min) : WITHIN2(x,min,max))
193 /* --- island struct and tree support functions --- */
195 #define ISLAND_ORTH(is,j,f,df) \
196 (is->f + (is->adj.points[(j)].off*is->adj.points[(j)].df))
198 #define ISLAND_ORTHX(is,j) ISLAND_ORTH(is,j,x,dx)
199 #define ISLAND_ORTHY(is,j) ISLAND_ORTH(is,j,y,dy)
201 static void fixup_islands_for_realloc(game_state *state)
205 for (i = 0; i < state->w*state->h; i++) state->gridi[i] = NULL;
206 for (i = 0; i < state->n_islands; i++) {
207 struct island *is = &state->islands[i];
209 INDEX(state, gridi, is->x, is->y) = is;
213 static int game_can_format_as_text_now(game_params *params)
218 static char *game_text_format(game_state *state)
225 len = (state->h) * (state->w+1) + 1;
226 ret = snewn(len, char);
229 for (y = 0; y < state->h; y++) {
230 for (x = 0; x < state->w; x++) {
231 grid = GRID(state,x,y);
232 nl = INDEX(state,lines,x,y);
233 is = INDEX(state, gridi, x, y);
235 *p++ = '0' + is->count;
236 } else if (grid & G_LINEV) {
237 *p++ = (nl > 1) ? '"' : (nl == 1) ? '|' : '!'; /* gaah, want a double-bar. */
238 } else if (grid & G_LINEH) {
239 *p++ = (nl > 1) ? '=' : (nl == 1) ? '-' : '~';
248 assert(p - ret == len);
252 static void debug_state(game_state *state)
254 char *textversion = game_text_format(state);
255 debug(("%s", textversion));
259 /*static void debug_possibles(game_state *state)
262 debug(("possh followed by possv\n"));
263 for (y = 0; y < state->h; y++) {
264 for (x = 0; x < state->w; x++) {
265 debug(("%d", POSSIBLES(state, 1, x, y)));
268 for (x = 0; x < state->w; x++) {
269 debug(("%d", POSSIBLES(state, 0, x, y)));
274 for (y = 0; y < state->h; y++) {
275 for (x = 0; x < state->w; x++) {
276 debug(("%d", MAXIMUM(state, 1, x, y)));
279 for (x = 0; x < state->w; x++) {
280 debug(("%d", MAXIMUM(state, 0, x, y)));
287 static void island_set_surrounds(struct island *is)
289 assert(INGRID(is->state,is->x,is->y));
290 is->adj.npoints = is->adj.nislands = 0;
291 #define ADDPOINT(cond,ddx,ddy) do {\
293 is->adj.points[is->adj.npoints].x = is->x+(ddx); \
294 is->adj.points[is->adj.npoints].y = is->y+(ddy); \
295 is->adj.points[is->adj.npoints].dx = (ddx); \
296 is->adj.points[is->adj.npoints].dy = (ddy); \
297 is->adj.points[is->adj.npoints].off = 0; \
300 ADDPOINT(is->x > 0, -1, 0);
301 ADDPOINT(is->x < (is->state->w-1), +1, 0);
302 ADDPOINT(is->y > 0, 0, -1);
303 ADDPOINT(is->y < (is->state->h-1), 0, +1);
306 static void island_find_orthogonal(struct island *is)
308 /* fills in the rest of the 'surrounds' structure, assuming
309 * all other islands are now in place. */
310 int i, x, y, dx, dy, off;
312 is->adj.nislands = 0;
313 for (i = 0; i < is->adj.npoints; i++) {
314 dx = is->adj.points[i].dx;
315 dy = is->adj.points[i].dy;
319 is->adj.points[i].off = 0;
320 while (INGRID(is->state, x, y)) {
321 if (GRID(is->state, x, y) & G_ISLAND) {
322 is->adj.points[i].off = off;
324 /*debug(("island (%d,%d) has orth is. %d*(%d,%d) away at (%d,%d).\n",
325 is->x, is->y, off, dx, dy,
326 ISLAND_ORTHX(is,i), ISLAND_ORTHY(is,i)));*/
329 off++; x += dx; y += dy;
336 static int island_hasbridge(struct island *is, int direction)
338 int x = is->adj.points[direction].x;
339 int y = is->adj.points[direction].y;
340 grid_type gline = is->adj.points[direction].dx ? G_LINEH : G_LINEV;
342 if (GRID(is->state, x, y) & gline) return 1;
346 static struct island *island_find_connection(struct island *is, int adjpt)
350 assert(adjpt < is->adj.npoints);
351 if (!is->adj.points[adjpt].off) return NULL;
352 if (!island_hasbridge(is, adjpt)) return NULL;
354 is_r = INDEX(is->state, gridi,
355 ISLAND_ORTHX(is, adjpt), ISLAND_ORTHY(is, adjpt));
361 static struct island *island_add(game_state *state, int x, int y, int count)
366 assert(!(GRID(state,x,y) & G_ISLAND));
367 GRID(state,x,y) |= G_ISLAND;
370 if (state->n_islands > state->n_islands_alloc) {
371 state->n_islands_alloc = state->n_islands * 2;
373 sresize(state->islands, state->n_islands_alloc, struct island);
376 is = &state->islands[state->n_islands-1];
378 memset(is, 0, sizeof(struct island));
383 island_set_surrounds(is);
386 fixup_islands_for_realloc(state);
388 INDEX(state, gridi, x, y) = is;
394 /* n = -1 means 'flip NOLINE flags [and set line to 0].' */
395 static void island_join(struct island *i1, struct island *i2, int n, int is_max)
397 game_state *state = i1->state;
400 assert(i1->state == i2->state);
401 assert(n >= -1 && n <= i1->state->maxb);
403 if (i1->x == i2->x) {
406 s = i1->y+1; e = i2->y-1;
408 s = i2->y+1; e = i1->y-1;
410 for (y = s; y <= e; y++) {
412 INDEX(state,maxv,x,y) = n;
415 GRID(state,x,y) ^= G_NOLINEV;
417 GRID(state,x,y) &= ~G_LINEV;
419 GRID(state,x,y) |= G_LINEV;
420 INDEX(state,lines,x,y) = n;
424 } else if (i1->y == i2->y) {
427 s = i1->x+1; e = i2->x-1;
429 s = i2->x+1; e = i1->x-1;
431 for (x = s; x <= e; x++) {
433 INDEX(state,maxh,x,y) = n;
436 GRID(state,x,y) ^= G_NOLINEH;
438 GRID(state,x,y) &= ~G_LINEH;
440 GRID(state,x,y) |= G_LINEH;
441 INDEX(state,lines,x,y) = n;
446 assert(!"island_join: islands not orthogonal.");
450 /* Counts the number of bridges currently attached to the island. */
451 static int island_countbridges(struct island *is)
455 for (i = 0; i < is->adj.npoints; i++) {
456 c += GRIDCOUNT(is->state,
457 is->adj.points[i].x, is->adj.points[i].y,
458 is->adj.points[i].dx ? G_LINEH : G_LINEV);
460 /*debug(("island count for (%d,%d) is %d.\n", is->x, is->y, c));*/
464 static int island_adjspace(struct island *is, int marks, int missing,
467 int x, y, poss, curr, dx;
468 grid_type gline, mline;
470 x = is->adj.points[direction].x;
471 y = is->adj.points[direction].y;
472 dx = is->adj.points[direction].dx;
473 gline = dx ? G_LINEH : G_LINEV;
476 mline = dx ? G_MARKH : G_MARKV;
477 if (GRID(is->state,x,y) & mline) return 0;
479 poss = POSSIBLES(is->state, dx, x, y);
480 poss = min(poss, missing);
482 curr = GRIDCOUNT(is->state, x, y, gline);
483 poss = min(poss, MAXIMUM(is->state, dx, x, y) - curr);
488 /* Counts the number of bridge spaces left around the island;
489 * expects the possibles to be up-to-date. */
490 static int island_countspaces(struct island *is, int marks)
492 int i, c = 0, missing;
494 missing = is->count - island_countbridges(is);
495 if (missing < 0) return 0;
497 for (i = 0; i < is->adj.npoints; i++) {
498 c += island_adjspace(is, marks, missing, i);
503 static int island_isadj(struct island *is, int direction)
506 grid_type gline, mline;
508 x = is->adj.points[direction].x;
509 y = is->adj.points[direction].y;
511 mline = is->adj.points[direction].dx ? G_MARKH : G_MARKV;
512 gline = is->adj.points[direction].dx ? G_LINEH : G_LINEV;
513 if (GRID(is->state, x, y) & mline) {
514 /* If we're marked (i.e. the thing to attach to is complete)
515 * only count an adjacency if we're already attached. */
516 return GRIDCOUNT(is->state, x, y, gline);
518 /* If we're unmarked, count possible adjacency iff it's
519 * flagged as POSSIBLE. */
520 return POSSIBLES(is->state, is->adj.points[direction].dx, x, y);
525 /* Counts the no. of possible adjacent islands (including islands
526 * we're already connected to). */
527 static int island_countadj(struct island *is)
531 for (i = 0; i < is->adj.npoints; i++) {
532 if (island_isadj(is, i)) nadj++;
537 static void island_togglemark(struct island *is)
540 struct island *is_loop;
542 /* mark the island... */
543 GRID(is->state, is->x, is->y) ^= G_MARK;
545 /* ...remove all marks on non-island squares... */
546 for (x = 0; x < is->state->w; x++) {
547 for (y = 0; y < is->state->h; y++) {
548 if (!(GRID(is->state, x, y) & G_ISLAND))
549 GRID(is->state, x, y) &= ~G_MARK;
553 /* ...and add marks to squares around marked islands. */
554 for (i = 0; i < is->state->n_islands; i++) {
555 is_loop = &is->state->islands[i];
556 if (!(GRID(is_loop->state, is_loop->x, is_loop->y) & G_MARK))
559 for (j = 0; j < is_loop->adj.npoints; j++) {
560 /* if this direction takes us to another island, mark all
561 * squares between the two islands. */
562 if (!is_loop->adj.points[j].off) continue;
563 assert(is_loop->adj.points[j].off > 1);
564 for (o = 1; o < is_loop->adj.points[j].off; o++) {
566 is_loop->x + is_loop->adj.points[j].dx*o,
567 is_loop->y + is_loop->adj.points[j].dy*o) |=
568 is_loop->adj.points[j].dy ? G_MARKV : G_MARKH;
574 static int island_impossible(struct island *is, int strict)
576 int curr = island_countbridges(is), nspc = is->count - curr, nsurrspc;
578 struct island *is_orth;
581 debug(("island at (%d,%d) impossible because full.\n", is->x, is->y));
582 return 1; /* too many bridges */
583 } else if ((curr + island_countspaces(is, 0)) < is->count) {
584 debug(("island at (%d,%d) impossible because not enough spaces.\n", is->x, is->y));
585 return 1; /* impossible to create enough bridges */
586 } else if (strict && curr < is->count) {
587 debug(("island at (%d,%d) impossible because locked.\n", is->x, is->y));
588 return 1; /* not enough bridges and island is locked */
591 /* Count spaces in surrounding islands. */
593 for (i = 0; i < is->adj.npoints; i++) {
594 int ifree, dx = is->adj.points[i].dx;
596 if (!is->adj.points[i].off) continue;
597 poss = POSSIBLES(is->state, dx,
598 is->adj.points[i].x, is->adj.points[i].y);
599 if (poss == 0) continue;
600 is_orth = INDEX(is->state, gridi,
601 ISLAND_ORTHX(is,i), ISLAND_ORTHY(is,i));
604 ifree = is_orth->count - island_countbridges(is_orth);
607 * ifree is the number of bridges unfilled in the other
608 * island, which is clearly an upper bound on the number
609 * of extra bridges this island may run to it.
611 * Another upper bound is the number of bridges unfilled
612 * on the specific line between here and there. We must
613 * take the minimum of both.
615 int bmax = MAXIMUM(is->state, dx,
616 is->adj.points[i].x, is->adj.points[i].y);
617 int bcurr = GRIDCOUNT(is->state,
618 is->adj.points[i].x, is->adj.points[i].y,
619 dx ? G_LINEH : G_LINEV);
620 assert(bcurr <= bmax);
621 nsurrspc += min(ifree, bmax - bcurr);
624 if (nsurrspc < nspc) {
625 debug(("island at (%d,%d) impossible: surr. islands %d spc, need %d.\n",
626 is->x, is->y, nsurrspc, nspc));
627 return 1; /* not enough spaces around surrounding islands to fill this one. */
633 /* --- Game parameter functions --- */
635 #define DEFAULT_PRESET 0
637 const struct game_params bridges_presets[] = {
638 { 7, 7, 2, 30, 10, 1, 0 },
639 { 7, 7, 2, 30, 10, 1, 1 },
640 { 7, 7, 2, 30, 10, 1, 2 },
641 { 10, 10, 2, 30, 10, 1, 0 },
642 { 10, 10, 2, 30, 10, 1, 1 },
643 { 10, 10, 2, 30, 10, 1, 2 },
644 { 15, 15, 2, 30, 10, 1, 0 },
645 { 15, 15, 2, 30, 10, 1, 1 },
646 { 15, 15, 2, 30, 10, 1, 2 },
649 static game_params *default_params(void)
651 game_params *ret = snew(game_params);
652 *ret = bridges_presets[DEFAULT_PRESET];
657 static int game_fetch_preset(int i, char **name, game_params **params)
662 if (i < 0 || i >= lenof(bridges_presets))
665 ret = default_params();
666 *ret = bridges_presets[i];
669 sprintf(buf, "%dx%d %s", ret->w, ret->h,
670 ret->difficulty == 0 ? "easy" :
671 ret->difficulty == 1 ? "medium" : "hard");
677 static void free_params(game_params *params)
682 static game_params *dup_params(game_params *params)
684 game_params *ret = snew(game_params);
685 *ret = *params; /* structure copy */
689 #define EATNUM(x) do { \
690 (x) = atoi(string); \
691 while (*string && isdigit((unsigned char)*string)) string++; \
694 static void decode_params(game_params *params, char const *string)
697 params->h = params->w;
698 if (*string == 'x') {
702 if (*string == 'i') {
704 EATNUM(params->islands);
706 if (*string == 'e') {
708 EATNUM(params->expansion);
710 if (*string == 'm') {
712 EATNUM(params->maxb);
714 params->allowloops = 1;
715 if (*string == 'L') {
717 params->allowloops = 0;
719 if (*string == 'd') {
721 EATNUM(params->difficulty);
725 static char *encode_params(game_params *params, int full)
730 sprintf(buf, "%dx%di%de%dm%d%sd%d",
731 params->w, params->h, params->islands, params->expansion,
732 params->maxb, params->allowloops ? "" : "L",
735 sprintf(buf, "%dx%dm%d%s", params->w, params->h,
736 params->maxb, params->allowloops ? "" : "L");
741 static config_item *game_configure(game_params *params)
746 ret = snewn(8, config_item);
748 ret[0].name = "Width";
749 ret[0].type = C_STRING;
750 sprintf(buf, "%d", params->w);
751 ret[0].sval = dupstr(buf);
754 ret[1].name = "Height";
755 ret[1].type = C_STRING;
756 sprintf(buf, "%d", params->h);
757 ret[1].sval = dupstr(buf);
760 ret[2].name = "Difficulty";
761 ret[2].type = C_CHOICES;
762 ret[2].sval = ":Easy:Medium:Hard";
763 ret[2].ival = params->difficulty;
765 ret[3].name = "Allow loops";
766 ret[3].type = C_BOOLEAN;
768 ret[3].ival = params->allowloops;
770 ret[4].name = "Max. bridges per direction";
771 ret[4].type = C_CHOICES;
772 ret[4].sval = ":1:2:3:4"; /* keep up-to-date with MAX_BRIDGES */
773 ret[4].ival = params->maxb - 1;
775 ret[5].name = "%age of island squares";
776 ret[5].type = C_CHOICES;
777 ret[5].sval = ":5%:10%:15%:20%:25%:30%";
778 ret[5].ival = (params->islands / 5)-1;
780 ret[6].name = "Expansion factor (%age)";
781 ret[6].type = C_CHOICES;
782 ret[6].sval = ":0%:10%:20%:30%:40%:50%:60%:70%:80%:90%:100%";
783 ret[6].ival = params->expansion / 10;
793 static game_params *custom_params(config_item *cfg)
795 game_params *ret = snew(game_params);
797 ret->w = atoi(cfg[0].sval);
798 ret->h = atoi(cfg[1].sval);
799 ret->difficulty = cfg[2].ival;
800 ret->allowloops = cfg[3].ival;
801 ret->maxb = cfg[4].ival + 1;
802 ret->islands = (cfg[5].ival + 1) * 5;
803 ret->expansion = cfg[6].ival * 10;
808 static char *validate_params(game_params *params, int full)
810 if (params->w < 3 || params->h < 3)
811 return "Width and height must be at least 3";
812 if (params->maxb < 1 || params->maxb > MAX_BRIDGES)
813 return "Too many bridges.";
815 if (params->islands <= 0 || params->islands > 30)
816 return "%age of island squares must be between 1% and 30%";
817 if (params->expansion < 0 || params->expansion > 100)
818 return "Expansion factor must be between 0 and 100";
823 /* --- Game encoding and differences --- */
825 static char *encode_game(game_state *state)
828 int wh = state->w*state->h, run, x, y;
831 ret = snewn(wh + 1, char);
834 for (y = 0; y < state->h; y++) {
835 for (x = 0; x < state->w; x++) {
836 is = INDEX(state, gridi, x, y);
839 *p++ = ('a'-1) + run;
843 *p++ = '0' + is->count;
845 *p++ = 'A' + (is->count - 10);
848 *p++ = ('a'-1) + run;
856 *p++ = ('a'-1) + run;
860 assert(p - ret <= wh);
865 static char *game_state_diff(game_state *src, game_state *dest)
867 int movesize = 256, movelen = 0;
868 char *move = snewn(movesize, char), buf[80];
870 grid_type gline, nline;
871 struct island *is_s, *is_d, *is_orth;
873 #define APPEND do { \
874 if (movelen + len >= movesize) { \
875 movesize = movelen + len + 256; \
876 move = sresize(move, movesize, char); \
878 strcpy(move + movelen, buf); \
882 move[movelen++] = 'S';
883 move[movelen] = '\0';
885 assert(src->n_islands == dest->n_islands);
887 for (i = 0; i < src->n_islands; i++) {
888 is_s = &src->islands[i];
889 is_d = &dest->islands[i];
890 assert(is_s->x == is_d->x);
891 assert(is_s->y == is_d->y);
892 assert(is_s->adj.npoints == is_d->adj.npoints); /* more paranoia */
894 for (d = 0; d < is_s->adj.npoints; d++) {
895 if (is_s->adj.points[d].dx == -1 ||
896 is_s->adj.points[d].dy == -1) continue;
898 x = is_s->adj.points[d].x;
899 y = is_s->adj.points[d].y;
900 gline = is_s->adj.points[d].dx ? G_LINEH : G_LINEV;
901 nline = is_s->adj.points[d].dx ? G_NOLINEH : G_NOLINEV;
902 is_orth = INDEX(dest, gridi,
903 ISLAND_ORTHX(is_d, d), ISLAND_ORTHY(is_d, d));
905 if (GRIDCOUNT(src, x, y, gline) != GRIDCOUNT(dest, x, y, gline)) {
907 len = sprintf(buf, ";L%d,%d,%d,%d,%d",
908 is_s->x, is_s->y, is_orth->x, is_orth->y,
909 GRIDCOUNT(dest, x, y, gline));
912 if ((GRID(src,x,y) & nline) != (GRID(dest, x, y) & nline)) {
914 len = sprintf(buf, ";N%d,%d,%d,%d",
915 is_s->x, is_s->y, is_orth->x, is_orth->y);
919 if ((GRID(src, is_s->x, is_s->y) & G_MARK) !=
920 (GRID(dest, is_d->x, is_d->y) & G_MARK)) {
921 len = sprintf(buf, ";M%d,%d", is_s->x, is_s->y);
928 /* --- Game setup and solving utilities --- */
930 /* This function is optimised; a Quantify showed that lots of grid-generation time
931 * (>50%) was spent in here. Hence the IDX() stuff. */
933 static void map_update_possibles(game_state *state)
935 int x, y, s, e, bl, i, np, maxb, w = state->w, idx;
936 struct island *is_s = NULL, *is_f = NULL;
938 /* Run down vertical stripes [un]setting possv... */
939 for (x = 0; x < state->w; x++) {
943 maxb = state->params.maxb; /* placate optimiser */
944 /* Unset possible flags until we find an island. */
945 for (y = 0; y < state->h; y++) {
946 is_s = IDX(state, gridi, idx);
952 IDX(state, possv, idx) = 0;
955 for (; y < state->h; y++) {
956 maxb = min(maxb, IDX(state, maxv, idx));
957 is_f = IDX(state, gridi, idx);
960 np = min(maxb, is_f->count);
963 for (i = s; i <= e; i++) {
964 INDEX(state, possv, x, i) = bl ? 0 : np;
973 if (IDX(state,grid,idx) & (G_LINEH|G_NOLINEV)) bl = 1;
978 for (i = s; i <= e; i++)
979 INDEX(state, possv, x, i) = 0;
983 /* ...and now do horizontal stripes [un]setting possh. */
984 /* can we lose this clone'n'hack? */
985 for (y = 0; y < state->h; y++) {
989 maxb = state->params.maxb; /* placate optimiser */
990 for (x = 0; x < state->w; x++) {
991 is_s = IDX(state, gridi, idx);
997 IDX(state, possh, idx) = 0;
1000 for (; x < state->w; x++) {
1001 maxb = min(maxb, IDX(state, maxh, idx));
1002 is_f = IDX(state, gridi, idx);
1005 np = min(maxb, is_f->count);
1008 for (i = s; i <= e; i++) {
1009 INDEX(state, possh, i, y) = bl ? 0 : np;
1018 if (IDX(state,grid,idx) & (G_LINEV|G_NOLINEH)) bl = 1;
1023 for (i = s; i <= e; i++)
1024 INDEX(state, possh, i, y) = 0;
1029 static void map_count(game_state *state)
1032 grid_type flag, grid;
1035 for (i = 0; i < state->n_islands; i++) {
1036 is = &state->islands[i];
1038 for (n = 0; n < is->adj.npoints; n++) {
1039 ax = is->adj.points[n].x;
1040 ay = is->adj.points[n].y;
1041 flag = (ax == is->x) ? G_LINEV : G_LINEH;
1042 grid = GRID(state,ax,ay);
1044 is->count += INDEX(state,lines,ax,ay);
1050 static void map_find_orthogonal(game_state *state)
1054 for (i = 0; i < state->n_islands; i++) {
1055 island_find_orthogonal(&state->islands[i]);
1059 static int grid_degree(game_state *state, int x, int y, int *nx_r, int *ny_r)
1061 grid_type grid = SCRATCH(state, x, y), gline = grid & G_LINE;
1063 int x1, y1, x2, y2, c = 0, i, nx, ny;
1065 nx = ny = -1; /* placate optimiser */
1066 is = INDEX(state, gridi, x, y);
1068 for (i = 0; i < is->adj.npoints; i++) {
1069 gline = is->adj.points[i].dx ? G_LINEH : G_LINEV;
1071 is->adj.points[i].x,
1072 is->adj.points[i].y) & gline) {
1073 nx = is->adj.points[i].x;
1074 ny = is->adj.points[i].y;
1079 if (gline & G_LINEV) {
1086 /* Non-island squares with edges in should never be pointing off the
1087 * edge of the grid. */
1088 assert(INGRID(state, x1, y1));
1089 assert(INGRID(state, x2, y2));
1090 if (SCRATCH(state, x1, y1) & (gline | G_ISLAND)) {
1091 nx = x1; ny = y1; c++;
1093 if (SCRATCH(state, x2, y2) & (gline | G_ISLAND)) {
1094 nx = x2; ny = y2; c++;
1098 assert(nx != -1 && ny != -1); /* paranoia */
1099 *nx_r = nx; *ny_r = ny;
1104 static int map_hasloops(game_state *state, int mark)
1106 int x, y, ox, oy, nx = 0, ny = 0, loop = 0;
1108 memcpy(state->scratch, state->grid, GRIDSZ(state));
1110 /* This algorithm is actually broken; if there are two loops connected
1111 * by bridges this will also highlight bridges. The correct algorithm
1112 * uses a dsf and a two-pass edge-detection algorithm (see check_correct
1113 * in slant.c); this is BALGE for now, especially since disallow-loops
1114 * is not the default for this puzzle. If we want to fix this later then
1115 * copy the alg in slant.c to the empty statement in map_group. */
1117 /* Remove all 1-degree edges. */
1118 for (y = 0; y < state->h; y++) {
1119 for (x = 0; x < state->w; x++) {
1121 while (grid_degree(state, ox, oy, &nx, &ny) == 1) {
1122 /*debug(("hasloops: removing 1-degree at (%d,%d).\n", ox, oy));*/
1123 SCRATCH(state, ox, oy) &= ~(G_LINE|G_ISLAND);
1128 /* Mark any remaining edges as G_WARN, if required. */
1129 for (x = 0; x < state->w; x++) {
1130 for (y = 0; y < state->h; y++) {
1131 if (GRID(state,x,y) & G_ISLAND) continue;
1133 if (SCRATCH(state, x, y) & G_LINE) {
1135 /*debug(("hasloops: marking loop square at (%d,%d).\n",
1137 GRID(state,x,y) |= G_WARN;
1140 return 1; /* short-cut as soon as we find one */
1143 GRID(state,x,y) &= ~G_WARN;
1150 static void map_group(game_state *state)
1152 int i, wh = state->w*state->h, d1, d2;
1154 int *dsf = state->solver->dsf;
1155 struct island *is, *is_join;
1157 /* Initialise dsf. */
1160 /* For each island, find connected islands right or down
1161 * and merge the dsf for the island squares as well as the
1162 * bridge squares. */
1163 for (x = 0; x < state->w; x++) {
1164 for (y = 0; y < state->h; y++) {
1165 GRID(state,x,y) &= ~(G_SWEEP|G_WARN); /* for group_full. */
1167 is = INDEX(state, gridi, x, y);
1170 for (i = 0; i < is->adj.npoints; i++) {
1171 /* only want right/down */
1172 if (is->adj.points[i].dx == -1 ||
1173 is->adj.points[i].dy == -1) continue;
1175 is_join = island_find_connection(is, i);
1176 if (!is_join) continue;
1178 d2 = DINDEX(is_join->x, is_join->y);
1179 if (dsf_canonify(dsf,d1) == dsf_canonify(dsf,d2)) {
1180 ; /* we have a loop. See comment in map_hasloops. */
1181 /* However, we still want to merge all squares joining
1182 * this side-that-makes-a-loop. */
1184 /* merge all squares between island 1 and island 2. */
1185 for (x2 = x; x2 <= is_join->x; x2++) {
1186 for (y2 = y; y2 <= is_join->y; y2++) {
1188 if (d1 != d2) dsf_merge(dsf,d1,d2);
1196 static int map_group_check(game_state *state, int canon, int warn,
1199 int *dsf = state->solver->dsf, nislands = 0;
1200 int x, y, i, allfull = 1;
1203 for (i = 0; i < state->n_islands; i++) {
1204 is = &state->islands[i];
1205 if (dsf_canonify(dsf, DINDEX(is->x,is->y)) != canon) continue;
1207 GRID(state, is->x, is->y) |= G_SWEEP;
1209 if (island_countbridges(is) != is->count)
1212 if (warn && allfull && nislands != state->n_islands) {
1213 /* we're full and this island group isn't the whole set.
1214 * Mark all squares with this dsf canon as ERR. */
1215 for (x = 0; x < state->w; x++) {
1216 for (y = 0; y < state->h; y++) {
1217 if (dsf_canonify(dsf, DINDEX(x,y)) == canon) {
1218 GRID(state,x,y) |= G_WARN;
1224 if (nislands_r) *nislands_r = nislands;
1228 static int map_group_full(game_state *state, int *ngroups_r)
1230 int *dsf = state->solver->dsf, ngroups = 0;
1234 /* NB this assumes map_group (or sth else) has cleared G_SWEEP. */
1236 for (i = 0; i < state->n_islands; i++) {
1237 is = &state->islands[i];
1238 if (GRID(state,is->x,is->y) & G_SWEEP) continue;
1241 if (map_group_check(state, dsf_canonify(dsf, DINDEX(is->x,is->y)),
1246 *ngroups_r = ngroups;
1250 static int map_check(game_state *state)
1254 /* Check for loops, if necessary. */
1255 if (!state->allowloops) {
1256 if (map_hasloops(state, 1))
1260 /* Place islands into island groups and check for early
1261 * satisfied-groups. */
1262 map_group(state); /* clears WARN and SWEEP */
1263 if (map_group_full(state, &ngroups)) {
1264 if (ngroups == 1) return 1;
1269 static void map_clear(game_state *state)
1273 for (x = 0; x < state->w; x++) {
1274 for (y = 0; y < state->h; y++) {
1275 /* clear most flags; might want to be slightly more careful here. */
1276 GRID(state,x,y) &= G_ISLAND;
1281 static void solve_join(struct island *is, int direction, int n, int is_max)
1283 struct island *is_orth;
1284 int d1, d2, *dsf = is->state->solver->dsf;
1285 game_state *state = is->state; /* for DINDEX */
1287 is_orth = INDEX(is->state, gridi,
1288 ISLAND_ORTHX(is, direction),
1289 ISLAND_ORTHY(is, direction));
1291 /*debug(("...joining (%d,%d) to (%d,%d) with %d bridge(s).\n",
1292 is->x, is->y, is_orth->x, is_orth->y, n));*/
1293 island_join(is, is_orth, n, is_max);
1295 if (n > 0 && !is_max) {
1296 d1 = DINDEX(is->x, is->y);
1297 d2 = DINDEX(is_orth->x, is_orth->y);
1298 if (dsf_canonify(dsf, d1) != dsf_canonify(dsf, d2))
1299 dsf_merge(dsf, d1, d2);
1303 static int solve_fillone(struct island *is)
1307 debug(("solve_fillone for island (%d,%d).\n", is->x, is->y));
1309 for (i = 0; i < is->adj.npoints; i++) {
1310 if (island_isadj(is, i)) {
1311 if (island_hasbridge(is, i)) {
1312 /* already attached; do nothing. */;
1314 solve_join(is, i, 1, 0);
1322 static int solve_fill(struct island *is)
1324 /* for each unmarked adjacent, make sure we convert every possible bridge
1325 * to a real one, and then work out the possibles afresh. */
1326 int i, nnew, ncurr, nadded = 0, missing;
1328 debug(("solve_fill for island (%d,%d).\n", is->x, is->y));
1330 missing = is->count - island_countbridges(is);
1331 if (missing < 0) return 0;
1333 /* very like island_countspaces. */
1334 for (i = 0; i < is->adj.npoints; i++) {
1335 nnew = island_adjspace(is, 1, missing, i);
1337 ncurr = GRIDCOUNT(is->state,
1338 is->adj.points[i].x, is->adj.points[i].y,
1339 is->adj.points[i].dx ? G_LINEH : G_LINEV);
1341 solve_join(is, i, nnew + ncurr, 0);
1348 static int solve_island_stage1(struct island *is, int *didsth_r)
1350 int bridges = island_countbridges(is);
1351 int nspaces = island_countspaces(is, 1);
1352 int nadj = island_countadj(is);
1357 /*debug(("island at (%d,%d) filled %d/%d (%d spc) nadj %d\n",
1358 is->x, is->y, bridges, is->count, nspaces, nadj));*/
1359 if (bridges > is->count) {
1360 /* We only ever add bridges when we're sure they fit, or that's
1361 * the only place they can go. If we've added bridges such that
1362 * another island has become wrong, the puzzle must not have had
1364 debug(("...island at (%d,%d) is overpopulated!\n", is->x, is->y));
1366 } else if (bridges == is->count) {
1367 /* This island is full. Make sure it's marked (and update
1368 * possibles if we did). */
1369 if (!(GRID(is->state, is->x, is->y) & G_MARK)) {
1370 debug(("...marking island (%d,%d) as full.\n", is->x, is->y));
1371 island_togglemark(is);
1374 } else if (GRID(is->state, is->x, is->y) & G_MARK) {
1375 debug(("...island (%d,%d) is marked but unfinished!\n",
1377 return 0; /* island has been marked unfinished; no solution from here. */
1379 /* This is the interesting bit; we try and fill in more information
1380 * about this island. */
1381 if (is->count == bridges + nspaces) {
1382 if (solve_fill(is) > 0) didsth = 1;
1383 } else if (is->count > ((nadj-1) * is->state->maxb)) {
1384 /* must have at least one bridge in each possible direction. */
1385 if (solve_fillone(is) > 0) didsth = 1;
1389 map_update_possibles(is->state);
1395 /* returns non-zero if a new line here would cause a loop. */
1396 static int solve_island_checkloop(struct island *is, int direction)
1398 struct island *is_orth;
1399 int *dsf = is->state->solver->dsf, d1, d2;
1400 game_state *state = is->state;
1402 if (is->state->allowloops) return 0; /* don't care anyway */
1403 if (island_hasbridge(is, direction)) return 0; /* already has a bridge */
1404 if (island_isadj(is, direction) == 0) return 0; /* no adj island */
1406 is_orth = INDEX(is->state, gridi,
1407 ISLAND_ORTHX(is,direction),
1408 ISLAND_ORTHY(is,direction));
1409 if (!is_orth) return 0;
1411 d1 = DINDEX(is->x, is->y);
1412 d2 = DINDEX(is_orth->x, is_orth->y);
1413 if (dsf_canonify(dsf, d1) == dsf_canonify(dsf, d2)) {
1414 /* two islands are connected already; don't join them. */
1420 static int solve_island_stage2(struct island *is, int *didsth_r)
1422 int added = 0, removed = 0, navail = 0, nadj, i;
1426 for (i = 0; i < is->adj.npoints; i++) {
1427 if (solve_island_checkloop(is, i)) {
1428 debug(("removing possible loop at (%d,%d) direction %d.\n",
1430 solve_join(is, i, -1, 0);
1431 map_update_possibles(is->state);
1434 navail += island_isadj(is, i);
1435 /*debug(("stage2: navail for (%d,%d) direction (%d,%d) is %d.\n",
1437 is->adj.points[i].dx, is->adj.points[i].dy,
1438 island_isadj(is, i)));*/
1442 /*debug(("island at (%d,%d) navail %d: checking...\n", is->x, is->y, navail));*/
1444 for (i = 0; i < is->adj.npoints; i++) {
1445 if (!island_hasbridge(is, i)) {
1446 nadj = island_isadj(is, i);
1447 if (nadj > 0 && (navail - nadj) < is->count) {
1448 /* we couldn't now complete the island without at
1449 * least one bridge here; put it in. */
1450 /*debug(("nadj %d, navail %d, is->count %d.\n",
1451 nadj, navail, is->count));*/
1452 debug(("island at (%d,%d) direction (%d,%d) must have 1 bridge\n",
1454 is->adj.points[i].dx, is->adj.points[i].dy));
1455 solve_join(is, i, 1, 0);
1457 /*debug_state(is->state);
1458 debug_possibles(is->state);*/
1462 if (added) map_update_possibles(is->state);
1463 if (added || removed) *didsth_r = 1;
1467 static int solve_island_subgroup(struct island *is, int direction)
1469 struct island *is_join;
1470 int nislands, *dsf = is->state->solver->dsf;
1471 game_state *state = is->state;
1473 debug(("..checking subgroups.\n"));
1475 /* if is isn't full, return 0. */
1476 if (island_countbridges(is) < is->count) {
1477 debug(("...orig island (%d,%d) not full.\n", is->x, is->y));
1481 if (direction >= 0) {
1482 is_join = INDEX(state, gridi,
1483 ISLAND_ORTHX(is, direction),
1484 ISLAND_ORTHY(is, direction));
1487 /* if is_join isn't full, return 0. */
1488 if (island_countbridges(is_join) < is_join->count) {
1489 debug(("...dest island (%d,%d) not full.\n",
1490 is_join->x, is_join->y));
1495 /* Check group membership for is->dsf; if it's full return 1. */
1496 if (map_group_check(state, dsf_canonify(dsf, DINDEX(is->x,is->y)),
1498 if (nislands < state->n_islands) {
1499 /* we have a full subgroup that isn't the whole set.
1500 * This isn't allowed. */
1501 debug(("island at (%d,%d) makes full subgroup, disallowing.\n",
1505 debug(("...has finished puzzle.\n"));
1511 static int solve_island_impossible(game_state *state)
1516 /* If any islands are impossible, return 1. */
1517 for (i = 0; i < state->n_islands; i++) {
1518 is = &state->islands[i];
1519 if (island_impossible(is, 0)) {
1520 debug(("island at (%d,%d) has become impossible, disallowing.\n",
1528 /* Bear in mind that this function is really rather inefficient. */
1529 static int solve_island_stage3(struct island *is, int *didsth_r)
1531 int i, n, x, y, missing, spc, curr, maxb, didsth = 0;
1532 int wh = is->state->w * is->state->h;
1533 struct solver_state *ss = is->state->solver;
1537 missing = is->count - island_countbridges(is);
1538 if (missing <= 0) return 1;
1540 for (i = 0; i < is->adj.npoints; i++) {
1541 x = is->adj.points[i].x;
1542 y = is->adj.points[i].y;
1543 spc = island_adjspace(is, 1, missing, i);
1544 if (spc == 0) continue;
1546 curr = GRIDCOUNT(is->state, x, y,
1547 is->adj.points[i].dx ? G_LINEH : G_LINEV);
1548 debug(("island at (%d,%d) s3, trying %d - %d bridges.\n",
1549 is->x, is->y, curr+1, curr+spc));
1551 /* Now we know that this island could have more bridges,
1552 * to bring the total from curr+1 to curr+spc. */
1554 /* We have to squirrel the dsf away and restore it afterwards;
1555 * it is additive only, and can't be removed from. */
1556 memcpy(ss->tmpdsf, ss->dsf, wh*sizeof(int));
1557 for (n = curr+1; n <= curr+spc; n++) {
1558 solve_join(is, i, n, 0);
1559 map_update_possibles(is->state);
1561 if (solve_island_subgroup(is, i) ||
1562 solve_island_impossible(is->state)) {
1564 debug(("island at (%d,%d) d(%d,%d) new max of %d bridges:\n",
1566 is->adj.points[i].dx, is->adj.points[i].dy,
1571 solve_join(is, i, curr, 0); /* put back to before. */
1572 memcpy(ss->dsf, ss->tmpdsf, wh*sizeof(int));
1575 /*debug_state(is->state);*/
1577 debug(("...adding NOLINE.\n"));
1578 solve_join(is, i, -1, 0); /* we can't have any bridges here. */
1580 debug(("...setting maximum\n"));
1581 solve_join(is, i, maxb, 1);
1585 map_update_possibles(is->state);
1588 for (i = 0; i < is->adj.npoints; i++) {
1590 * Now check to see if any currently empty direction must have
1591 * at least one bridge in order to avoid forming an isolated
1592 * subgraph. This differs from the check above in that it
1593 * considers multiple target islands. For example:
1600 * The example on the left can be handled by the above loop:
1601 * it will observe that connecting the central 2 twice to the
1602 * left would form an isolated subgraph, and hence it will
1603 * restrict that 2 to at most one bridge in that direction.
1604 * But the example on the right won't be handled by that loop,
1605 * because the deduction requires us to imagine connecting the
1606 * 3 to _both_ the 1 and 2 at once to form an isolated
1609 * This pass is necessary _as well_ as the above one, because
1610 * neither can do the other's job. In the left one,
1611 * restricting the direction which _would_ cause trouble can
1612 * be done even if it's not yet clear which of the remaining
1613 * directions has to have a compensatory bridge; whereas the
1614 * pass below that can handle the right-hand example does need
1615 * to know what direction to point the necessary bridge in.
1617 * Neither pass can handle the most general case, in which we
1618 * observe that an arbitrary subset of an island's neighbours
1619 * would form an isolated subgraph with it if it connected
1620 * maximally to them, and hence that at least one bridge must
1621 * point to some neighbour outside that subset but we don't
1622 * know which neighbour. To handle that, we'd have to have a
1623 * richer data format for the solver, which could cope with
1624 * recording the idea that at least one of two edges must have
1631 spc = island_adjspace(is, 1, missing, i);
1632 if (spc == 0) continue;
1634 for (j = 0; j < is->adj.npoints; j++)
1635 before[j] = GRIDCOUNT(is->state,
1636 is->adj.points[j].x,
1637 is->adj.points[j].y,
1638 is->adj.points[j].dx ? G_LINEH : G_LINEV);
1639 if (before[i] != 0) continue; /* this idea is pointless otherwise */
1641 memcpy(ss->tmpdsf, ss->dsf, wh*sizeof(int));
1643 for (j = 0; j < is->adj.npoints; j++) {
1644 spc = island_adjspace(is, 1, missing, j);
1645 if (spc == 0) continue;
1646 if (j == i) continue;
1647 solve_join(is, j, before[j] + spc, 0);
1649 map_update_possibles(is->state);
1651 if (solve_island_subgroup(is, -1))
1654 for (j = 0; j < is->adj.npoints; j++)
1655 solve_join(is, j, before[j], 0);
1656 memcpy(ss->dsf, ss->tmpdsf, wh*sizeof(int));
1659 debug(("island at (%d,%d) must connect in direction (%d,%d) to"
1660 " avoid full subgroup.\n",
1661 is->x, is->y, is->adj.points[i].dx, is->adj.points[i].dy));
1662 solve_join(is, i, 1, 0);
1666 map_update_possibles(is->state);
1669 if (didsth) *didsth_r = didsth;
1673 #define CONTINUE_IF_FULL do { \
1674 if (GRID(state, is->x, is->y) & G_MARK) { \
1675 /* island full, don't try fixing it */ \
1679 static int solve_sub(game_state *state, int difficulty, int depth)
1687 /* First island iteration: things we can work out by looking at
1688 * properties of the island as a whole. */
1689 for (i = 0; i < state->n_islands; i++) {
1690 is = &state->islands[i];
1691 if (!solve_island_stage1(is, &didsth)) return 0;
1693 if (didsth) continue;
1694 else if (difficulty < 1) break;
1696 /* Second island iteration: thing we can work out by looking at
1697 * properties of individual island connections. */
1698 for (i = 0; i < state->n_islands; i++) {
1699 is = &state->islands[i];
1701 if (!solve_island_stage2(is, &didsth)) return 0;
1703 if (didsth) continue;
1704 else if (difficulty < 2) break;
1706 /* Third island iteration: things we can only work out by looking
1707 * at groups of islands. */
1708 for (i = 0; i < state->n_islands; i++) {
1709 is = &state->islands[i];
1710 if (!solve_island_stage3(is, &didsth)) return 0;
1712 if (didsth) continue;
1713 else if (difficulty < 3) break;
1715 /* If we can be bothered, write a recursive solver to finish here. */
1718 if (map_check(state)) return 1; /* solved it */
1722 static void solve_for_hint(game_state *state)
1725 solve_sub(state, 10, 0);
1728 static int solve_from_scratch(game_state *state, int difficulty)
1732 map_update_possibles(state);
1733 return solve_sub(state, difficulty, 0);
1736 /* --- New game functions --- */
1738 static game_state *new_state(game_params *params)
1740 game_state *ret = snew(game_state);
1741 int wh = params->w * params->h, i;
1745 ret->allowloops = params->allowloops;
1746 ret->maxb = params->maxb;
1747 ret->params = *params;
1749 ret->grid = snewn(wh, grid_type);
1750 memset(ret->grid, 0, GRIDSZ(ret));
1751 ret->scratch = snewn(wh, grid_type);
1752 memset(ret->scratch, 0, GRIDSZ(ret));
1754 ret->wha = snewn(wh*N_WH_ARRAYS, char);
1755 memset(ret->wha, 0, wh*N_WH_ARRAYS*sizeof(char));
1757 ret->possv = ret->wha;
1758 ret->possh = ret->wha + wh;
1759 ret->lines = ret->wha + wh*2;
1760 ret->maxv = ret->wha + wh*3;
1761 ret->maxh = ret->wha + wh*4;
1763 memset(ret->maxv, ret->maxb, wh*sizeof(char));
1764 memset(ret->maxh, ret->maxb, wh*sizeof(char));
1766 ret->islands = NULL;
1768 ret->n_islands_alloc = 0;
1770 ret->gridi = snewn(wh, struct island *);
1771 for (i = 0; i < wh; i++) ret->gridi[i] = NULL;
1773 ret->solved = ret->completed = 0;
1775 ret->solver = snew(struct solver_state);
1776 ret->solver->dsf = snew_dsf(wh);
1777 ret->solver->tmpdsf = snewn(wh, int);
1779 ret->solver->refcount = 1;
1784 static game_state *dup_game(game_state *state)
1786 game_state *ret = snew(game_state);
1787 int wh = state->w*state->h;
1791 ret->allowloops = state->allowloops;
1792 ret->maxb = state->maxb;
1793 ret->params = state->params;
1795 ret->grid = snewn(wh, grid_type);
1796 memcpy(ret->grid, state->grid, GRIDSZ(ret));
1797 ret->scratch = snewn(wh, grid_type);
1798 memcpy(ret->scratch, state->scratch, GRIDSZ(ret));
1800 ret->wha = snewn(wh*N_WH_ARRAYS, char);
1801 memcpy(ret->wha, state->wha, wh*N_WH_ARRAYS*sizeof(char));
1803 ret->possv = ret->wha;
1804 ret->possh = ret->wha + wh;
1805 ret->lines = ret->wha + wh*2;
1806 ret->maxv = ret->wha + wh*3;
1807 ret->maxh = ret->wha + wh*4;
1809 ret->islands = snewn(state->n_islands, struct island);
1810 memcpy(ret->islands, state->islands, state->n_islands * sizeof(struct island));
1811 ret->n_islands = ret->n_islands_alloc = state->n_islands;
1813 ret->gridi = snewn(wh, struct island *);
1814 fixup_islands_for_realloc(ret);
1816 ret->solved = state->solved;
1817 ret->completed = state->completed;
1819 ret->solver = state->solver;
1820 ret->solver->refcount++;
1825 static void free_game(game_state *state)
1827 if (--state->solver->refcount <= 0) {
1828 sfree(state->solver->dsf);
1829 sfree(state->solver->tmpdsf);
1830 sfree(state->solver);
1833 sfree(state->islands);
1834 sfree(state->gridi);
1838 sfree(state->scratch);
1843 #define MAX_NEWISLAND_TRIES 50
1844 #define MIN_SENSIBLE_ISLANDS 3
1846 #define ORDER(a,b) do { if (a < b) { int tmp=a; int a=b; int b=tmp; } } while(0)
1848 static char *new_game_desc(game_params *params, random_state *rs,
1849 char **aux, int interactive)
1851 game_state *tobuild = NULL;
1852 int i, j, wh = params->w * params->h, x, y, dx, dy;
1853 int minx, miny, maxx, maxy, joinx, joiny, newx, newy, diffx, diffy;
1854 int ni_req = max((params->islands * wh) / 100, MIN_SENSIBLE_ISLANDS), ni_curr, ni_bad;
1855 struct island *is, *is2;
1857 unsigned int echeck;
1859 /* pick a first island position randomly. */
1861 if (tobuild) free_game(tobuild);
1862 tobuild = new_state(params);
1864 x = random_upto(rs, params->w);
1865 y = random_upto(rs, params->h);
1866 island_add(tobuild, x, y, 0);
1869 debug(("Created initial island at (%d,%d).\n", x, y));
1871 while (ni_curr < ni_req) {
1872 /* Pick a random island to try and extend from. */
1873 i = random_upto(rs, tobuild->n_islands);
1874 is = &tobuild->islands[i];
1876 /* Pick a random direction to extend in. */
1877 j = random_upto(rs, is->adj.npoints);
1878 dx = is->adj.points[j].x - is->x;
1879 dy = is->adj.points[j].y - is->y;
1881 /* Find out limits of where we could put a new island. */
1883 minx = is->x + 2*dx; miny = is->y + 2*dy; /* closest is 2 units away. */
1884 x = is->x+dx; y = is->y+dy;
1885 if (GRID(tobuild,x,y) & (G_LINEV|G_LINEH)) {
1886 /* already a line next to the island, continue. */
1890 if (x < 0 || x >= params->w || y < 0 || y >= params->h) {
1891 /* got past the edge; put a possible at the island
1893 maxx = x-dx; maxy = y-dy;
1896 if (GRID(tobuild,x,y) & G_ISLAND) {
1897 /* could join up to an existing island... */
1898 joinx = x; joiny = y;
1899 /* ... or make a new one 2 spaces away. */
1900 maxx = x - 2*dx; maxy = y - 2*dy;
1902 } else if (GRID(tobuild,x,y) & (G_LINEV|G_LINEH)) {
1903 /* could make a new one 1 space away from the line. */
1904 maxx = x - dx; maxy = y - dy;
1911 debug(("Island at (%d,%d) with d(%d,%d) has new positions "
1912 "(%d,%d) -> (%d,%d), join (%d,%d).\n",
1913 is->x, is->y, dx, dy, minx, miny, maxx, maxy, joinx, joiny));
1914 /* Now we know where we could either put a new island
1915 * (between min and max), or (if loops are allowed) could join on
1916 * to an existing island (at join). */
1917 if (params->allowloops && joinx != -1 && joiny != -1) {
1918 if (random_upto(rs, 100) < (unsigned long)params->expansion) {
1919 is2 = INDEX(tobuild, gridi, joinx, joiny);
1920 debug(("Joining island at (%d,%d) to (%d,%d).\n",
1921 is->x, is->y, is2->x, is2->y));
1925 diffx = (maxx - minx) * dx;
1926 diffy = (maxy - miny) * dy;
1927 if (diffx < 0 || diffy < 0) goto bad;
1928 if (random_upto(rs,100) < (unsigned long)params->expansion) {
1929 newx = maxx; newy = maxy;
1930 debug(("Creating new island at (%d,%d) (expanded).\n", newx, newy));
1932 newx = minx + random_upto(rs,diffx+1)*dx;
1933 newy = miny + random_upto(rs,diffy+1)*dy;
1934 debug(("Creating new island at (%d,%d).\n", newx, newy));
1936 /* check we're not next to island in the other orthogonal direction. */
1937 if ((INGRID(tobuild,newx+dy,newy+dx) && (GRID(tobuild,newx+dy,newy+dx) & G_ISLAND)) ||
1938 (INGRID(tobuild,newx-dy,newy-dx) && (GRID(tobuild,newx-dy,newy-dx) & G_ISLAND))) {
1939 debug(("New location is adjacent to island, skipping.\n"));
1942 is2 = island_add(tobuild, newx, newy, 0);
1943 /* Must get is again at this point; the array might have
1944 * been realloced by island_add... */
1945 is = &tobuild->islands[i]; /* ...but order will not change. */
1947 ni_curr++; ni_bad = 0;
1949 island_join(is, is2, random_upto(rs, tobuild->maxb)+1, 0);
1950 debug_state(tobuild);
1955 if (ni_bad > MAX_NEWISLAND_TRIES) {
1956 debug(("Unable to create any new islands after %d tries; "
1957 "created %d [%d%%] (instead of %d [%d%%] requested).\n",
1958 MAX_NEWISLAND_TRIES,
1959 ni_curr, ni_curr * 100 / wh,
1960 ni_req, ni_req * 100 / wh));
1967 debug(("Only generated one island (!), retrying.\n"));
1970 /* Check we have at least one island on each extremity of the grid. */
1972 for (x = 0; x < params->w; x++) {
1973 if (INDEX(tobuild, gridi, x, 0)) echeck |= 1;
1974 if (INDEX(tobuild, gridi, x, params->h-1)) echeck |= 2;
1976 for (y = 0; y < params->h; y++) {
1977 if (INDEX(tobuild, gridi, 0, y)) echeck |= 4;
1978 if (INDEX(tobuild, gridi, params->w-1, y)) echeck |= 8;
1981 debug(("Generated grid doesn't fill to sides, retrying.\n"));
1986 map_find_orthogonal(tobuild);
1988 if (params->difficulty > 0) {
1989 if ((ni_curr > MIN_SENSIBLE_ISLANDS) &&
1990 (solve_from_scratch(tobuild, params->difficulty-1) > 0)) {
1991 debug(("Grid is solvable at difficulty %d (too easy); retrying.\n",
1992 params->difficulty-1));
1997 if (solve_from_scratch(tobuild, params->difficulty) == 0) {
1998 debug(("Grid not solvable at difficulty %d, (too hard); retrying.\n",
1999 params->difficulty));
2003 /* ... tobuild is now solved. We rely on this making the diff for aux. */
2004 debug_state(tobuild);
2005 ret = encode_game(tobuild);
2007 game_state *clean = dup_game(tobuild);
2009 map_update_possibles(clean);
2010 *aux = game_state_diff(clean, tobuild);
2018 static char *validate_desc(game_params *params, char *desc)
2020 int i, wh = params->w * params->h;
2022 for (i = 0; i < wh; i++) {
2023 if (*desc >= '1' && *desc <= '9')
2025 else if (*desc >= 'a' && *desc <= 'z')
2026 i += *desc - 'a'; /* plus the i++ */
2027 else if (*desc >= 'A' && *desc <= 'G')
2029 else if (*desc == 'V' || *desc == 'W' ||
2030 *desc == 'X' || *desc == 'Y' ||
2031 *desc == 'H' || *desc == 'I' ||
2032 *desc == 'J' || *desc == 'K')
2035 return "Game description shorter than expected";
2037 return "Game description containers unexpected character";
2040 if (*desc || i > wh)
2041 return "Game description longer than expected";
2046 static game_state *new_game_sub(game_params *params, char *desc)
2048 game_state *state = new_state(params);
2051 debug(("new_game[_sub]: desc = '%s'.\n", desc));
2053 for (y = 0; y < params->h; y++) {
2054 for (x = 0; x < params->w; x++) {
2060 if (c >= 'a' && c <= 'z')
2070 case '1': case '2': case '3': case '4':
2071 case '5': case '6': case '7': case '8': case '9':
2072 island_add(state, x, y, (c - '0'));
2075 case 'A': case 'B': case 'C': case 'D':
2076 case 'E': case 'F': case 'G':
2077 island_add(state, x, y, (c - 'A') + 10);
2085 assert(!"Malformed desc.");
2090 if (*desc) assert(!"Over-long desc.");
2092 map_find_orthogonal(state);
2093 map_update_possibles(state);
2098 static game_state *new_game(midend *me, game_params *params, char *desc)
2100 return new_game_sub(params, desc);
2104 int dragx_src, dragy_src; /* source; -1 means no drag */
2105 int dragx_dst, dragy_dst; /* src's closest orth island. */
2107 int dragging, drag_is_noline, nlines;
2109 int cur_x, cur_y, cur_visible; /* cursor position */
2113 static char *ui_cancel_drag(game_ui *ui)
2115 ui->dragx_src = ui->dragy_src = -1;
2116 ui->dragx_dst = ui->dragy_dst = -1;
2121 static game_ui *new_ui(game_state *state)
2123 game_ui *ui = snew(game_ui);
2125 ui->cur_x = state->islands[0].x;
2126 ui->cur_y = state->islands[0].y;
2127 ui->cur_visible = 0;
2132 static void free_ui(game_ui *ui)
2137 static char *encode_ui(game_ui *ui)
2142 static void decode_ui(game_ui *ui, char *encoding)
2146 static void game_changed_state(game_ui *ui, game_state *oldstate,
2147 game_state *newstate)
2151 struct game_drawstate {
2156 int started, dragging;
2160 static char *update_drag_dst(game_state *state, game_ui *ui,
2161 const game_drawstate *ds, int nx, int ny)
2163 int ox, oy, dx, dy, i, currl, maxb;
2165 grid_type gtype, ntype, mtype, curr;
2167 if (ui->dragx_src == -1 || ui->dragy_src == -1) return NULL;
2172 /* work out which of the four directions we're closest to... */
2173 ox = COORD(ui->dragx_src) + TILE_SIZE/2;
2174 oy = COORD(ui->dragy_src) + TILE_SIZE/2;
2176 if (abs(nx-ox) < abs(ny-oy)) {
2178 dy = (ny-oy) < 0 ? -1 : 1;
2179 gtype = G_LINEV; ntype = G_NOLINEV; mtype = G_MARKV;
2180 maxb = INDEX(state, maxv, ui->dragx_src+dx, ui->dragy_src+dy);
2183 dx = (nx-ox) < 0 ? -1 : 1;
2184 gtype = G_LINEH; ntype = G_NOLINEH; mtype = G_MARKH;
2185 maxb = INDEX(state, maxh, ui->dragx_src+dx, ui->dragy_src+dy);
2187 if (ui->drag_is_noline) {
2190 curr = GRID(state, ui->dragx_src+dx, ui->dragy_src+dy);
2191 currl = INDEX(state, lines, ui->dragx_src+dx, ui->dragy_src+dy);
2194 if (currl == maxb) {
2199 ui->nlines = currl + 1;
2207 /* ... and see if there's an island off in that direction. */
2208 is = INDEX(state, gridi, ui->dragx_src, ui->dragy_src);
2209 for (i = 0; i < is->adj.npoints; i++) {
2210 if (is->adj.points[i].off == 0) continue;
2211 curr = GRID(state, is->x+dx, is->y+dy);
2212 if (curr & mtype) continue; /* don't allow changes to marked lines. */
2213 if (ui->drag_is_noline) {
2214 if (curr & gtype) continue; /* no no-line where already a line */
2216 if (POSSIBLES(state, dx, is->x+dx, is->y+dy) == 0) continue; /* no line if !possible. */
2217 if (curr & ntype) continue; /* can't have a bridge where there's a no-line. */
2220 if (is->adj.points[i].dx == dx &&
2221 is->adj.points[i].dy == dy) {
2222 ui->dragx_dst = ISLAND_ORTHX(is,i);
2223 ui->dragy_dst = ISLAND_ORTHY(is,i);
2226 /*debug(("update_drag src (%d,%d) d(%d,%d) dst (%d,%d)\n",
2227 ui->dragx_src, ui->dragy_src, dx, dy,
2228 ui->dragx_dst, ui->dragy_dst));*/
2232 static char *finish_drag(game_state *state, game_ui *ui)
2236 if (ui->dragx_src == -1 || ui->dragy_src == -1)
2238 if (ui->dragx_dst == -1 || ui->dragy_dst == -1)
2239 return ui_cancel_drag(ui);
2241 if (ui->drag_is_noline) {
2242 sprintf(buf, "N%d,%d,%d,%d",
2243 ui->dragx_src, ui->dragy_src,
2244 ui->dragx_dst, ui->dragy_dst);
2246 sprintf(buf, "L%d,%d,%d,%d,%d",
2247 ui->dragx_src, ui->dragy_src,
2248 ui->dragx_dst, ui->dragy_dst, ui->nlines);
2256 static char *interpret_move(game_state *state, game_ui *ui, const game_drawstate *ds,
2257 int x, int y, int button)
2259 int gx = FROMCOORD(x), gy = FROMCOORD(y);
2261 grid_type ggrid = INGRID(state,gx,gy) ? GRID(state,gx,gy) : 0;
2263 if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
2264 if (!INGRID(state, gx, gy)) return NULL;
2265 ui->cur_visible = 0;
2266 if ((ggrid & G_ISLAND) && !(ggrid & G_MARK)) {
2271 return ui_cancel_drag(ui);
2272 } else if (button == LEFT_DRAG || button == RIGHT_DRAG) {
2273 if (gx != ui->dragx_src || gy != ui->dragy_src) {
2275 ui->drag_is_noline = (button == RIGHT_DRAG) ? 1 : 0;
2276 return update_drag_dst(state, ui, ds, x, y);
2278 /* cancel a drag when we go back to the starting point */
2283 } else if (button == LEFT_RELEASE || button == RIGHT_RELEASE) {
2285 return finish_drag(state, ui);
2288 if (!INGRID(state, gx, gy)) return NULL;
2289 if (!(GRID(state, gx, gy) & G_ISLAND)) return NULL;
2290 sprintf(buf, "M%d,%d", gx, gy);
2293 } else if (button == 'h' || button == 'H') {
2294 game_state *solved = dup_game(state);
2295 solve_for_hint(solved);
2296 ret = game_state_diff(state, solved);
2299 } else if (IS_CURSOR_MOVE(button)) {
2300 ui->cur_visible = 1;
2302 int nx = ui->cur_x, ny = ui->cur_y;
2304 move_cursor(button, &nx, &ny, state->w, state->h, 0);
2305 update_drag_dst(state, ui, ds,
2306 COORD(nx)+TILE_SIZE/2,
2307 COORD(ny)+TILE_SIZE/2);
2308 return finish_drag(state, ui);
2310 int dx = (button == CURSOR_RIGHT) ? +1 : (button == CURSOR_LEFT) ? -1 : 0;
2311 int dy = (button == CURSOR_DOWN) ? +1 : (button == CURSOR_UP) ? -1 : 0;
2312 int dorthx = 1 - abs(dx), dorthy = 1 - abs(dy);
2313 int dir, orth, nx = x, ny = y;
2315 /* 'orthorder' is a tweak to ensure that if you press RIGHT and
2316 * happen to move upwards, when you press LEFT you then tend
2317 * downwards (rather than upwards again). */
2318 int orthorder = (button == CURSOR_LEFT || button == CURSOR_UP) ? 1 : -1;
2320 /* This attempts to find an island in the direction you're
2321 * asking for, broadly speaking. If you ask to go right, for
2322 * example, it'll look for islands to the right and slightly
2323 * above or below your current horiz. position, allowing
2324 * further above/below the further away it searches. */
2326 assert(GRID(state, ui->cur_x, ui->cur_y) & G_ISLAND);
2327 /* currently this is depth-first (so orthogonally-adjacent
2328 * islands across the other side of the grid will be moved to
2329 * before closer islands slightly offset). Swap the order of
2330 * these two loops to change to breadth-first search. */
2331 for (orth = 0; ; orth++) {
2333 for (dir = 1; ; dir++) {
2336 if (orth > dir) continue; /* only search in cone outwards. */
2338 nx = ui->cur_x + dir*dx + orth*dorthx*orthorder;
2339 ny = ui->cur_y + dir*dy + orth*dorthy*orthorder;
2340 if (INGRID(state, nx, ny)) {
2341 dingrid = oingrid = 1;
2342 if (GRID(state, nx, ny) & G_ISLAND) goto found;
2345 nx = ui->cur_x + dir*dx - orth*dorthx*orthorder;
2346 ny = ui->cur_y + dir*dy - orth*dorthy*orthorder;
2347 if (INGRID(state, nx, ny)) {
2348 dingrid = oingrid = 1;
2349 if (GRID(state, nx, ny) & G_ISLAND) goto found;
2352 if (!dingrid) break;
2354 if (!oingrid) return "";
2363 } else if (IS_CURSOR_SELECT(button)) {
2364 if (!ui->cur_visible) {
2365 ui->cur_visible = 1;
2370 if (ui->dragx_dst == -1 && ui->dragy_dst == -1) {
2371 sprintf(buf, "M%d,%d", ui->cur_x, ui->cur_y);
2376 grid_type v = GRID(state, ui->cur_x, ui->cur_y);
2379 ui->dragx_src = ui->cur_x;
2380 ui->dragy_src = ui->cur_y;
2381 ui->dragx_dst = ui->dragy_dst = -1;
2382 ui->drag_is_noline = (button == CURSOR_SELECT2) ? 1 : 0;
2386 } else if (button == 'g' || button == 'G') {
2387 ui->show_hints = 1 - ui->show_hints;
2394 static game_state *execute_move(game_state *state, char *move)
2396 game_state *ret = dup_game(state);
2397 int x1, y1, x2, y2, nl, n;
2398 struct island *is1, *is2;
2401 debug(("execute_move: %s\n", move));
2403 if (!*move) goto badmove;
2409 } else if (c == 'L') {
2410 if (sscanf(move, "%d,%d,%d,%d,%d%n",
2411 &x1, &y1, &x2, &y2, &nl, &n) != 5)
2413 if (!INGRID(ret, x1, y1) || !INGRID(ret, x2, y2))
2415 is1 = INDEX(ret, gridi, x1, y1);
2416 is2 = INDEX(ret, gridi, x2, y2);
2417 if (!is1 || !is2) goto badmove;
2418 if (nl < 0 || nl > state->maxb) goto badmove;
2419 island_join(is1, is2, nl, 0);
2420 } else if (c == 'N') {
2421 if (sscanf(move, "%d,%d,%d,%d%n",
2422 &x1, &y1, &x2, &y2, &n) != 4)
2424 if (!INGRID(ret, x1, y1) || !INGRID(ret, x2, y2))
2426 is1 = INDEX(ret, gridi, x1, y1);
2427 is2 = INDEX(ret, gridi, x2, y2);
2428 if (!is1 || !is2) goto badmove;
2429 island_join(is1, is2, -1, 0);
2430 } else if (c == 'M') {
2431 if (sscanf(move, "%d,%d%n",
2434 if (!INGRID(ret, x1, y1))
2436 is1 = INDEX(ret, gridi, x1, y1);
2437 if (!is1) goto badmove;
2438 island_togglemark(is1);
2445 else if (*move) goto badmove;
2448 map_update_possibles(ret);
2449 if (map_check(ret)) {
2450 debug(("Game completed.\n"));
2456 debug(("%s: unrecognised move.\n", move));
2461 static char *solve_game(game_state *state, game_state *currstate,
2462 char *aux, char **error)
2468 debug(("solve_game: aux = %s\n", aux));
2469 solved = execute_move(state, aux);
2471 *error = "Generated aux string is not a valid move (!).";
2475 solved = dup_game(state);
2476 /* solve with max strength... */
2477 if (solve_from_scratch(solved, 10) == 0) {
2479 *error = "Game does not have a (non-recursive) solution.";
2483 ret = game_state_diff(currstate, solved);
2485 debug(("solve_game: ret = %s\n", ret));
2489 /* ----------------------------------------------------------------------
2493 static void game_compute_size(game_params *params, int tilesize,
2496 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2497 struct { int tilesize; } ads, *ds = &ads;
2498 ads.tilesize = tilesize;
2500 *x = TILE_SIZE * params->w + 2 * BORDER;
2501 *y = TILE_SIZE * params->h + 2 * BORDER;
2504 static void game_set_size(drawing *dr, game_drawstate *ds,
2505 game_params *params, int tilesize)
2507 ds->tilesize = tilesize;
2510 static float *game_colours(frontend *fe, int *ncolours)
2512 float *ret = snewn(3 * NCOLOURS, float);
2515 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
2517 for (i = 0; i < 3; i++) {
2518 ret[COL_FOREGROUND * 3 + i] = 0.0F;
2519 ret[COL_HINT * 3 + i] = ret[COL_LOWLIGHT * 3 + i];
2520 ret[COL_GRID * 3 + i] =
2521 (ret[COL_HINT * 3 + i] + ret[COL_BACKGROUND * 3 + i]) * 0.5F;
2522 ret[COL_MARK * 3 + i] = ret[COL_HIGHLIGHT * 3 + i];
2524 ret[COL_WARNING * 3 + 0] = 1.0F;
2525 ret[COL_WARNING * 3 + 1] = 0.25F;
2526 ret[COL_WARNING * 3 + 2] = 0.25F;
2528 ret[COL_SELECTED * 3 + 0] = 0.25F;
2529 ret[COL_SELECTED * 3 + 1] = 1.00F;
2530 ret[COL_SELECTED * 3 + 2] = 0.25F;
2532 ret[COL_CURSOR * 3 + 0] = min(ret[COL_BACKGROUND * 3 + 0] * 1.4F, 1.0F);
2533 ret[COL_CURSOR * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.8F;
2534 ret[COL_CURSOR * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.8F;
2536 *ncolours = NCOLOURS;
2540 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
2542 struct game_drawstate *ds = snew(struct game_drawstate);
2543 int wh = state->w*state->h;
2549 ds->grid = snewn(wh, grid_type);
2550 memset(ds->grid, -1, wh*sizeof(grid_type));
2551 ds->lv = snewn(wh, int);
2552 ds->lh = snewn(wh, int);
2553 memset(ds->lv, 0, wh*sizeof(int));
2554 memset(ds->lh, 0, wh*sizeof(int));
2560 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
2568 #define LINE_WIDTH (TILE_SIZE/8)
2569 #define TS8(x) (((x)*TILE_SIZE)/8)
2571 #define OFFSET(thing) ((TILE_SIZE/2) - ((thing)/2))
2573 static void lines_vert(drawing *dr, game_drawstate *ds,
2574 int ox, int oy, int lv, int col, grid_type v)
2576 int lw = LINE_WIDTH, gw = LINE_WIDTH, bw, i, loff;
2577 while ((bw = lw * lv + gw * (lv+1)) > TILE_SIZE)
2581 draw_rect(dr, ox + loff, oy, bw, TILE_SIZE, COL_MARK);
2582 for (i = 0; i < lv; i++, loff += lw + gw)
2583 draw_rect(dr, ox + loff + gw, oy, lw, TILE_SIZE, col);
2586 static void lines_horiz(drawing *dr, game_drawstate *ds,
2587 int ox, int oy, int lh, int col, grid_type v)
2589 int lw = LINE_WIDTH, gw = LINE_WIDTH, bw, i, loff;
2590 while ((bw = lw * lh + gw * (lh+1)) > TILE_SIZE)
2594 draw_rect(dr, ox, oy + loff, TILE_SIZE, bw, COL_MARK);
2595 for (i = 0; i < lh; i++, loff += lw + gw)
2596 draw_rect(dr, ox, oy + loff + gw, TILE_SIZE, lw, col);
2599 static void line_cross(drawing *dr, game_drawstate *ds,
2600 int ox, int oy, int col, grid_type v)
2603 draw_line(dr, ox, oy, ox+off, oy+off, col);
2604 draw_line(dr, ox+off, oy, ox, oy+off, col);
2607 static int between_island(game_state *state, int sx, int sy, int dx, int dy)
2609 int x = sx - dx, y = sy - dy;
2611 while (INGRID(state, x, y)) {
2612 if (GRID(state, x, y) & G_ISLAND) goto found;
2617 x = sx + dx, y = sy + dy;
2618 while (INGRID(state, x, y)) {
2619 if (GRID(state, x, y) & G_ISLAND) return 1;
2625 static void lines_lvlh(game_state *state, game_ui *ui, int x, int y, grid_type v,
2626 int *lv_r, int *lh_r)
2630 if (v & G_LINEV) lv = INDEX(state,lines,x,y);
2631 if (v & G_LINEH) lh = INDEX(state,lines,x,y);
2633 if (ui->show_hints) {
2634 if (between_island(state, x, y, 0, 1) && !lv) lv = 1;
2635 if (between_island(state, x, y, 1, 0) && !lh) lh = 1;
2637 /*debug(("lvlh: (%d,%d) v 0x%x lv %d lh %d.\n", x, y, v, lv, lh));*/
2638 *lv_r = lv; *lh_r = lh;
2641 static void dsf_debug_draw(drawing *dr,
2642 game_state *state, game_drawstate *ds,
2646 int ts = TILE_SIZE/2;
2647 int ox = COORD(x) + ts/2, oy = COORD(y) + ts/2;
2650 sprintf(str, "%d", dsf_canonify(state->solver->dsf, DINDEX(x,y)));
2651 draw_text(dr, ox, oy, FONT_VARIABLE, ts,
2652 ALIGN_VCENTRE | ALIGN_HCENTRE, COL_WARNING, str);
2656 static void lines_redraw(drawing *dr,
2657 game_state *state, game_drawstate *ds, game_ui *ui,
2658 int x, int y, grid_type v, int lv, int lh)
2660 int ox = COORD(x), oy = COORD(y);
2661 int vcol = (v & G_FLASH) ? COL_HIGHLIGHT :
2662 (v & G_WARN) ? COL_WARNING : COL_FOREGROUND, hcol = vcol;
2663 grid_type todraw = v & G_NOLINE;
2666 if (ui->todraw & G_FLAGSH) hcol = COL_SELECTED;
2667 if (ui->todraw & G_FLAGSV) vcol = COL_SELECTED;
2668 todraw |= ui->todraw;
2671 draw_rect(dr, ox, oy, TILE_SIZE, TILE_SIZE, COL_BACKGROUND);
2673 draw_rect(dr, ox+TILE_SIZE/4, oy+TILE_SIZE/4,
2674 TILE_SIZE/2, TILE_SIZE/2, COL_CURSOR);*/
2677 if (ui->show_hints) {
2678 if (between_island(state, x, y, 0, 1) && !(v & G_LINEV))
2680 if (between_island(state, x, y, 1, 0) && !(v & G_LINEH))
2684 draw_rect_outline(dr, ox, oy, TILE_SIZE, TILE_SIZE, COL_GRID);
2687 if (todraw & G_NOLINEV) {
2688 line_cross(dr, ds, ox + TS8(3), oy + TS8(1), vcol, todraw);
2689 line_cross(dr, ds, ox + TS8(3), oy + TS8(5), vcol, todraw);
2691 if (todraw & G_NOLINEH) {
2692 line_cross(dr, ds, ox + TS8(1), oy + TS8(3), hcol, todraw);
2693 line_cross(dr, ds, ox + TS8(5), oy + TS8(3), hcol, todraw);
2695 /* if we're drawing a real line and a hint, make sure we draw the real
2697 if (lv && vcol == COL_HINT) lines_vert(dr, ds, ox, oy, lv, vcol, v);
2698 if (lh) lines_horiz(dr, ds, ox, oy, lh, hcol, v);
2699 if (lv && vcol != COL_HINT) lines_vert(dr, ds, ox, oy, lv, vcol, v);
2701 dsf_debug_draw(dr, state, ds, x, y);
2702 draw_update(dr, ox, oy, TILE_SIZE, TILE_SIZE);
2705 #define ISLAND_RADIUS ((TILE_SIZE*12)/20)
2706 #define ISLAND_NUMSIZE(is) \
2707 (((is)->count < 10) ? (TILE_SIZE*7)/10 : (TILE_SIZE*5)/10)
2709 static void island_redraw(drawing *dr,
2710 game_state *state, game_drawstate *ds,
2711 struct island *is, grid_type v)
2713 /* These overlap the edges of their squares, which is why they're drawn later.
2714 * We know they can't overlap each other because they're not allowed within 2
2715 * squares of each other. */
2716 int half = TILE_SIZE/2;
2717 int ox = COORD(is->x) + half, oy = COORD(is->y) + half;
2718 int orad = ISLAND_RADIUS, irad = orad - LINE_WIDTH;
2719 int updatesz = orad*2+1;
2720 int tcol = (v & G_FLASH) ? COL_HIGHLIGHT :
2721 (v & G_WARN) ? COL_WARNING : COL_FOREGROUND;
2722 int col = (v & G_ISSEL) ? COL_SELECTED : tcol;
2723 int bg = (v & G_CURSOR) ? COL_CURSOR :
2724 (v & G_MARK) ? COL_MARK : COL_BACKGROUND;
2728 draw_rect_outline(dr, COORD(is->x), COORD(is->y),
2729 TILE_SIZE, TILE_SIZE, COL_GRID);
2732 /* draw a thick circle */
2733 draw_circle(dr, ox, oy, orad, col, col);
2734 draw_circle(dr, ox, oy, irad, bg, bg);
2736 sprintf(str, "%d", is->count);
2737 draw_text(dr, ox, oy, FONT_VARIABLE, ISLAND_NUMSIZE(is),
2738 ALIGN_VCENTRE | ALIGN_HCENTRE, tcol, str);
2740 dsf_debug_draw(dr, state, ds, is->x, is->y);
2741 draw_update(dr, ox - orad, oy - orad, updatesz, updatesz);
2744 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
2745 game_state *state, int dir, game_ui *ui,
2746 float animtime, float flashtime)
2748 int x, y, force = 0, i, j, redraw, lv, lh;
2749 grid_type v, dsv, flash = 0;
2750 struct island *is, *is_drag_src = NULL, *is_drag_dst = NULL;
2753 int f = (int)(flashtime * 5 / FLASH_TIME);
2754 if (f == 1 || f == 3) flash = G_FLASH;
2757 /* Clear screen, if required. */
2760 TILE_SIZE * ds->w + 2 * BORDER,
2761 TILE_SIZE * ds->h + 2 * BORDER, COL_BACKGROUND);
2763 draw_rect_outline(dr,
2764 COORD(0)-1, COORD(0)-1,
2765 TILE_SIZE * ds->w + 2, TILE_SIZE * ds->h + 2,
2768 draw_update(dr, 0, 0,
2769 TILE_SIZE * ds->w + 2 * BORDER,
2770 TILE_SIZE * ds->h + 2 * BORDER);
2775 if (ui->dragx_src != -1 && ui->dragy_src != -1) {
2777 is_drag_src = INDEX(state, gridi, ui->dragx_src, ui->dragy_src);
2778 assert(is_drag_src);
2779 if (ui->dragx_dst != -1 && ui->dragy_dst != -1) {
2780 is_drag_dst = INDEX(state, gridi, ui->dragx_dst, ui->dragy_dst);
2781 assert(is_drag_dst);
2786 if (ui->show_hints != ds->show_hints) {
2788 ds->show_hints = ui->show_hints;
2791 /* Draw all lines (and hints, if we want), but *not* islands. */
2792 for (x = 0; x < ds->w; x++) {
2793 for (y = 0; y < ds->h; y++) {
2794 v = GRID(state, x, y) | flash;
2795 dsv = GRID(ds,x,y) & ~G_REDRAW;
2797 if (v & G_ISLAND) continue;
2800 if (WITHIN(x,is_drag_src->x, is_drag_dst->x) &&
2801 WITHIN(y,is_drag_src->y, is_drag_dst->y))
2804 lines_lvlh(state, ui, x, y, v, &lv, &lh);
2806 /*if (ui->cur_visible && ui->cur_x == x && ui->cur_y == y)
2810 lv != INDEX(ds,lv,x,y) ||
2811 lh != INDEX(ds,lh,x,y) ||
2813 GRID(ds, x, y) = v | G_REDRAW;
2814 INDEX(ds,lv,x,y) = lv;
2815 INDEX(ds,lh,x,y) = lh;
2816 lines_redraw(dr, state, ds, ui, x, y, v, lv, lh);
2818 GRID(ds,x,y) &= ~G_REDRAW;
2823 for (i = 0; i < state->n_islands; i++) {
2824 is = &state->islands[i];
2825 v = GRID(state, is->x, is->y) | flash;
2828 for (j = 0; j < is->adj.npoints; j++) {
2829 if (GRID(ds,is->adj.points[j].x,is->adj.points[j].y) & G_REDRAW) {
2835 if (is == is_drag_src)
2837 else if (is_drag_dst && is == is_drag_dst)
2841 if (island_impossible(is, v & G_MARK)) v |= G_WARN;
2843 if (ui->cur_visible && ui->cur_x == is->x && ui->cur_y == is->y)
2846 if ((v != GRID(ds, is->x, is->y)) || force || redraw) {
2847 GRID(ds,is->x,is->y) = v;
2848 island_redraw(dr, state, ds, is, v);
2853 static float game_anim_length(game_state *oldstate, game_state *newstate,
2854 int dir, game_ui *ui)
2859 static float game_flash_length(game_state *oldstate, game_state *newstate,
2860 int dir, game_ui *ui)
2862 if (!oldstate->completed && newstate->completed &&
2863 !oldstate->solved && !newstate->solved)
2869 static int game_status(game_state *state)
2871 return state->completed ? +1 : 0;
2874 static int game_timing_state(game_state *state, game_ui *ui)
2879 static void game_print_size(game_params *params, float *x, float *y)
2883 /* 10mm squares by default. */
2884 game_compute_size(params, 1000, &pw, &ph);
2889 static void game_print(drawing *dr, game_state *state, int ts)
2891 int ink = print_mono_colour(dr, 0);
2892 int paper = print_mono_colour(dr, 1);
2893 int x, y, cx, cy, i, nl;
2897 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2898 game_drawstate ads, *ds = &ads;
2901 /* I don't think this wants a border. */
2904 loff = ts / (8 * sqrt((state->params.maxb - 1)));
2905 print_line_width(dr, ts / 12);
2906 for (x = 0; x < state->w; x++) {
2907 for (y = 0; y < state->h; y++) {
2908 cx = COORD(x); cy = COORD(y);
2909 grid = GRID(state,x,y);
2910 nl = INDEX(state,lines,x,y);
2912 if (grid & G_ISLAND) continue;
2913 if (grid & G_LINEV) {
2914 for (i = 0; i < nl; i++)
2915 draw_line(dr, cx+ts/2+(2*i-nl+1)*loff, cy,
2916 cx+ts/2+(2*i-nl+1)*loff, cy+ts, ink);
2918 if (grid & G_LINEH) {
2919 for (i = 0; i < nl; i++)
2920 draw_line(dr, cx, cy+ts/2+(2*i-nl+1)*loff,
2921 cx+ts, cy+ts/2+(2*i-nl+1)*loff, ink);
2927 for (i = 0; i < state->n_islands; i++) {
2929 struct island *is = &state->islands[i];
2930 grid = GRID(state, is->x, is->y);
2931 cx = COORD(is->x) + ts/2;
2932 cy = COORD(is->y) + ts/2;
2934 draw_circle(dr, cx, cy, ISLAND_RADIUS, paper, ink);
2936 sprintf(str, "%d", is->count);
2937 draw_text(dr, cx, cy, FONT_VARIABLE, ISLAND_NUMSIZE(is),
2938 ALIGN_VCENTRE | ALIGN_HCENTRE, ink, str);
2943 #define thegame bridges
2946 const struct game thegame = {
2947 "Bridges", "games.bridges", "bridges",
2954 TRUE, game_configure, custom_params,
2962 TRUE, game_can_format_as_text_now, game_text_format,
2970 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
2973 game_free_drawstate,
2978 TRUE, FALSE, game_print_size, game_print,
2979 FALSE, /* wants_statusbar */
2980 FALSE, game_timing_state,
2981 REQUIRE_RBUTTON, /* flags */
2984 /* vim: set shiftwidth=4 tabstop=8: */